<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>

    <div v-if="!isLogin">
        <a href="javascript:void (0)">注册</a>
        <a href="javascript:void (0)" @click="isLogin=true" >登录</a>
    </div>

    <div v-else>
        <input type="text" v-model="newName">
        <input type="button" value="添加" @click="arr.push(newName)">
        <a href="javascript:void (0)"  @click="isLogin=false">登出</a>

    </div>


    <ul>
        <li v-for="name in arr">{{name}}</li>
    </ul>


</div>

<script src="js/vue.js"></script>

<script>
    let v = new Vue({
        el:"div",
        newName:"",
        data:{
           arr:["刘备","关羽"],
            isLogin:false,
        },

    })
</script>

</body>
</html>